1 files changed, 147 insertions, 0 deletions
diff --git a/llvm/test/Transforms/DeadStoreElimination/simple.ll b/llvm/test/Transforms/DeadStoreElimination/simple.ll
index 2ffe0539098..4f6221db245 100644
--- a/llvm/test/Transforms/DeadStoreElimination/simple.ll
+++ b/llvm/test/Transforms/DeadStoreElimination/simple.ll
@@ -350,3 +350,150 @@ define i8* @test25(i8* %p) nounwind {
   store i8 %tmp, i8* %p.4, align 1
   ret i8* %q
 }
+
+; Remove redundant store if loaded value is in another block.
+; CHECK-LABEL: @test26(
+; CHECK-NOT: store
+; CHECK: ret
+define i32 @test26(i1 %c, i32* %p) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  store i32 %v, i32* %p, align 4
+  br label %bb3
+bb3:
+  ret i32 0
+}
+
+; Remove redundant store if loaded value is in another block.
+; CHECK-LABEL: @test27(
+; CHECK-NOT: store
+; CHECK: ret
+define i32 @test27(i1 %c, i32* %p) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  br label %bb3
+bb3:
+  store i32 %v, i32* %p, align 4
+  ret i32 0
+}
+
+; Don't remove redundant store because of may-aliased store.
+; CHECK-LABEL: @test28(
+; CHECK: bb3:
+; CHECK-NEXT: store i32 %v
+define i32 @test28(i1 %c, i32* %p, i32* %p2, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+
+  ; Might overwrite value at %p
+  store i32 %i, i32* %p2, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  br label %bb3
+bb3:
+  store i32 %v, i32* %p, align 4
+  ret i32 0
+}
+
+; Don't remove redundant store because of may-aliased store.
+; CHECK-LABEL: @test29(
+; CHECK: bb3:
+; CHECK-NEXT: store i32 %v
+define i32 @test29(i1 %c, i32* %p, i32* %p2, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  ; Might overwrite value at %p
+  store i32 %i, i32* %p2, align 4
+  br label %bb3
+bb3:
+  store i32 %v, i32* %p, align 4
+  ret i32 0
+}
+
+declare void @unknown_func()
+
+; Don't remove redundant store because of unknown call.
+; CHECK-LABEL: @test30(
+; CHECK: bb3:
+; CHECK-NEXT: store i32 %v
+define i32 @test30(i1 %c, i32* %p, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br i1 %c, label %bb1, label %bb2
+bb1:
+  br label %bb3
+bb2:
+  ; Might overwrite value at %p
+  call void @unknown_func()
+  br label %bb3
+bb3:
+  store i32 %v, i32* %p, align 4
+  ret i32 0
+}
+
+; Remove redundant store if loaded value is in another block inside a loop.
+; CHECK-LABEL: @test31(
+; CHECK-NOT: store
+; CHECK: ret
+define i32 @test31(i1 %c, i32* %p, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br label %bb1
+bb1:
+  store i32 %v, i32* %p, align 4
+  br i1 undef, label %bb1, label %bb2
+bb2:
+  ret i32 0
+}
+
+; Don't remove redundant store in a loop with a may-alias store.
+; CHECK-LABEL: @test32(
+; CHECK: bb1:
+; CHECK-NEXT: store i32 %v
+; CHECK-NEXT: call void @unknown_func
+define i32 @test32(i1 %c, i32* %p, i32 %i) {
+entry:
+  %v = load i32, i32* %p, align 4
+  br label %bb1
+bb1:
+  store i32 %v, i32* %p, align 4
+  ; Might read and overwrite value at %p
+  call void @unknown_func()
+  br i1 undef, label %bb1, label %bb2
+bb2:
+  ret i32 0
+}
+
+; Remove redundant store, which is in the lame loop as the load.
+; CHECK-LABEL: @test33(
+; CHECK-NOT: store
+; CHECK: ret
+define i32 @test33(i1 %c, i32* %p, i32 %i) {
+entry:
+  br label %bb1
+bb1:
+  %v = load i32, i32* %p, align 4
+  br label %bb2
+bb2:
+  store i32 %v, i32* %p, align 4
+  ; Might read and overwrite value at %p, but doesn't matter.
+  call void @unknown_func()
+  br i1 undef, label %bb1, label %bb3
+bb3:
+  ret i32 0
+}
+